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The distribution of tardigrades in North America remains poorly known. Although a few areas have been intensively sampled, much of the continent has never been surveyed. Only four species have been reported in the state of Michigan: Macrobiotus hufelandi and Isohypsibius prosostomus on Isle Royale in Lake Superior, and Hexapodibius pilatoi and Diphascon {Adropion) belgicae in soil from the Lower Peninsula. In July 2005 I collected cryptogams from woodlands in the Upper Peninsula. Sites in all of the Upper Peninsulas 15 counties were sampled. Eleven tardigrade species were present in these mosses and lichens: the heterotardigrade Echiniscus virginicus and the eutardigrades Diphascon (Diphascon) iltisi, D. (D.) stappersi, Hypsibius arcticus, H. calcaratus, Ramazzottius baumanni, Macrobiotus echinogenitus, Macrobiotus cf. hufelandia, Macrobiotus tonollii, Minibiotus intermedius, and Milnesium tartigradum. The most widely distributed tardigrades were the cosmopolitan species Milnesium tardigradum and Minibiotus intermedius. The known distribution of Echiniscus vinginicus and D. (D.) stappersi in North America was hitherto limited to the southeastern United States.

The distribution of limnoterrestrial tardigrades in the American south is poorly known. This is especially true in the Gulf Coast states. There is only one published record of tardigrades from Louisiana. Nine species were found in two sites in southwestern Louisiana. We collected samples of lichens and mosses from fifteen sites in southeastern Louisiana, encompassing all parishes east of the Mississippi River. Sampling was not quantitative. The sites chosen included both natural woodlands and highly disturbed habitats. The collected material was soaked in deionized water overnight, allowing anhydrobiotic tardigrades to become active. Tardigrades were then mounted in Hoyer's medium for identification. The species collected included Echiniscus cavagnaroi, E. kofordi, Milnesium tardigradum, Macrobiotus cf. hufelandi, M. tonollfi, M. cf. harmsworthi, Minibiotus intermedius, Minibiotus fallax, Doryphoribius citrinus, and one Macrobiotus sp. new to science. D. citrinus has not previously been found in North America. The other species found in southeastern Louisiana are found in similar habitats in Florida.